A. L. Austin observed, in a letter written to Charles Darwin in 1877, that a composite of two faces was strikingly attractive. Mr. Austin placed two different portraits in a stereoscope and noticed that they fused into a single portrait. He wrote: “The faces blend in the most remarkable manner, producing in case of some ladies portraits, in every instance, a decided improvement in beauty” (Galt...

Cells need backward motor to move forward ytoplasmic dynein associates with a variety of intracellular cargos and pulls them toward the minus ends of microubules. But this retrograde motor protein is also essential for forward cell migration, as Dujardin et al. demonstrate on page 1205. After observing dynein and its associated regulatory proteins at the leading edges of migrating cells in a mo...